shaka-packager/packager/media/formats/mp4/fragmenter.h

131 lines
4.0 KiB
C++

// Copyright 2014 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#ifndef PACKAGER_MEDIA_FORMATS_MP4_FRAGMENTER_H_
#define PACKAGER_MEDIA_FORMATS_MP4_FRAGMENTER_H_
#include <memory>
#include <vector>
#include <absl/log/check.h>
#include <absl/log/log.h>
#include <packager/macros.h>
#include <packager/status/status.h>
namespace shaka {
namespace media {
class BufferWriter;
class MediaSample;
class StreamInfo;
namespace mp4 {
struct KeyFrameInfo;
struct SegmentReference;
struct TrackFragment;
/// Fragmenter is responsible for the generation of MP4 fragments, i.e. 'traf'
/// box and corresponding 'mdat' box.
class Fragmenter {
public:
/// @param info contains stream information.
/// @param traf points to a TrackFragment box.
/// @param edit_list_offset is the edit list offset that is encoded in Edit
/// List. It should be 0 if there is no EditList.
Fragmenter(std::shared_ptr<const StreamInfo> info,
TrackFragment* traf,
int64_t edit_list_offset);
~Fragmenter();
/// Add a sample to the fragmenter.
/// @param sample points to the sample to be added.
/// @return OK on success, an error status otherwise.
Status AddSample(const MediaSample& sample);
/// Initialize the fragment with default data.
/// @param first_sample_dts specifies the decoding timestamp for the first
/// sample for this fragment.
/// @return OK on success, an error status otherwise.
Status InitializeFragment(int64_t first_sample_dts);
/// Finalize and optimize the fragment.
Status FinalizeFragment();
/// Fill @a reference with current fragment information.
void GenerateSegmentReference(SegmentReference* reference) const;
void ClearFragmentFinalized() { fragment_finalized_ = false; }
int64_t fragment_duration() const { return fragment_duration_; }
int64_t first_sap_time() const { return first_sap_time_; }
int64_t earliest_presentation_time() const {
return earliest_presentation_time_;
}
bool fragment_initialized() const { return fragment_initialized_; }
bool fragment_finalized() const { return fragment_finalized_; }
BufferWriter* data() { return data_.get(); }
const std::vector<KeyFrameInfo>& key_frame_infos() const {
return key_frame_infos_;
}
protected:
TrackFragment* traf() { return traf_; }
/// Optimize sample entries table. If all values in @a entries are identical,
/// then @a entries is cleared and the value is assigned to @a default_value;
/// otherwise it is a NOP. Return true if the table is optimized.
template <typename T>
bool OptimizeSampleEntries(std::vector<T>* entries, T* default_value);
private:
Status FinalizeFragmentForEncryption();
// Check if the current fragment starts with SAP.
bool StartsWithSAP() const;
std::shared_ptr<const StreamInfo> stream_info_;
TrackFragment* traf_ = nullptr;
int64_t edit_list_offset_ = 0;
int64_t seek_preroll_ = 0;
bool fragment_initialized_ = false;
bool fragment_finalized_ = false;
int64_t fragment_duration_ = 0;
int64_t earliest_presentation_time_ = 0;
int64_t first_sap_time_ = 0;
std::unique_ptr<BufferWriter> data_;
// Saves key frames information, for Video.
std::vector<KeyFrameInfo> key_frame_infos_;
DISALLOW_COPY_AND_ASSIGN(Fragmenter);
};
template <typename T>
bool Fragmenter::OptimizeSampleEntries(std::vector<T>* entries,
T* default_value) {
DCHECK(entries);
DCHECK(default_value);
DCHECK(!entries->empty());
typename std::vector<T>::const_iterator it = entries->begin();
T value = *it;
for (; it < entries->end(); ++it)
if (value != *it)
return false;
// Clear |entries| if it contains only one value.
entries->clear();
*default_value = value;
return true;
}
} // namespace mp4
} // namespace media
} // namespace shaka
#endif // PACKAGER_MEDIA_FORMATS_MP4_FRAGMENTER_H_